What the Poling Autism Case Means

The widely publicized court victory for the family who claimed vaccines
caused autism in their daughter does not prove a link.

Rahul K. Parikh, M.D.
March 13, 2008

For the past decade, advocacy groups have claimed that vaccines
cause autism, a behavior and language disorder, in children. At the center
of the debate is a compound called thimerosal, a mercury-based preservative
that was used in most vaccines until around 2001. Many of the advocates,
including Robert F. Kennedy Jr. in Salon, have accused doctors,
drug companies, and the federal government of hiding the truth about thimerosal
and its connection to autism.

Despite the charges, multiple studies have demonstrated no connection between
thimerosal (or anything else about vaccines) and autism. In the past nine
months alone, at least three studies have shown that thimerosal has no relationship
to autism or any other neurological disorders [1-3]. One study, published
in the January issue of Archives of General Psychiatry, looked at
autism rates in California after the removal of thimerosal. Not only did
the rates not go down, they continued to rise [3]. For these reasons, the
government and most doctors stand by the belief that vaccines are effective
and safe.

However, last week, the U.S. government awarded compensation to a Georgia
family, the Polings, who had sued the government (along with 5,000 other
families whose children have autism), claiming vaccines had caused autism
in their now 9-year-old daughter, Hannah. As the decision made headlines,
antivaccine groups claimed victory and vindication, and parents fretted over
whether to vaccinate their children.

This is the real danger of this case. As a pediatrician, I hate to see parents
pass up the chance to give their kids vaccines, which have saved countless
lives, prevented some of the deadliest diseases in human history and remain
safe. So what should we make of the Poling decision? Let me take it one point
at a time.

What did the government decide?

For many years now, the federal government has set aside funds for children
who have been injured by vaccines. Doctors and other health professionals
can report adverse outcomes to the government, and parents can file claims
in federal "vaccine
court." The court's judges, known as special
masters, review claims. If they find a child was injured by a vaccine, they
award compensation to that child.

In this case, "CHILD [Hannah Poling] v. Secretary of Health and Human
Services," the court "concluded that the facts of this case meet
the statutory criteria for demonstrating that the vaccinations CHILD received
on July 19, 2000, significantly aggravated an underlying mitochondrial disorder,
which predisposed her to deficits in cellular energy metabolism, and manifested
as a regressive encephalopathy with features of autism spectrum disorder.
Therefore, respondent recommends that compensation be awarded to petitioners."

Does that mean vaccines caused Hannah to become autistic?

No. Look again at the court statement: Hannah has "an underlying mitochondrial
disorder, which predisposed her to deficits in cellular energy metabolism,
and manifested as a regressive encephalopathy with features of autistic spectrum
disorder." Throughout the document, both Hannah's doctors and lab results
support the diagnosis of mitochondrial disorder.

Not a diagnosis of autism?

Right. Mitochondrial disorder does not equal autism. Generally speaking,
mitochondria are the parts of our cells that help generate energy. When they
fail, the body's cells go awry, which can lead to failures in any number
of normal body functions. There are at least 40 known mitochondrial disorders,
and probably many more we haven't yet found. But it's clear from the transcript
of the court's decision that this was not a case of vaccines causing autism.
Rather, this is a case where the court deemed it plausible that vaccines
aggravated an underlying disease caused by bad mitochondria, and that some
of the symptoms Hannah showed were similar to autism. As you'll see below,
there are even questions about that conclusion.

Advocacy groups, which maintain that vaccines did cause Hannah to develop
autism, point to two things in the court's statement. One is the phrase "features
consistent with autism spectrum disorder"; the second is an evaluation
by a team at the Center for Autism and Related Disorders. The document states
that clinicians Alice Kau and Kelley Duff believed Hannah was "developmentally
delayed and demonstrated features of autistic disorder." One thing that's
not clear in the document is what kind of "clinicians" these two
individuals are. Were they expert enough to consider a metabolic disorder
like mitochondrial diseases when they evaluated Hannah? That's a fundamental
question: Clinicians (doctors or otherwise) must consider not just the obvious
diagnosis, but a differential set of diagnoses as well. Because the government
has not released details of the case, which remain sealed according to court
rules, we do not know what evidence Kau and Duff relied upon to reach their
conclusion.

It's worth noting that the Poling case is not as rare or newsworthy as it
may appear, as it is not the first time the vaccine court has reached the
conclusion to compensate a child with autismlike symptoms. Kathleen Seidel,
a librarian and mother of a teenager with "autism spectrum diagnosis," maintains
Neurodiversity.com, a comprehensive Web site on autism research. She notes
nine prior cases "in which compensation was awarded for the lifelong
care of children and young adults who were diagnosed with autism or related
conditions after they sustained documented, verifiable vaccine injuries." However,
she adds, "the autism diagnosis followed the development or aggravation
of profoundly disabling physical conditions," and "in no instance
has the VICP [Vaccine Injury Compensation Program] awarded compensation to
cognitively disabled individuals who were not also physically disabled."

Is autism related to mitochondrial disorders?

It could be. But this question needs a lot more study. Could there be kids
walking around who carry the diagnosis of autism, or some other unspecified
developmental disorder, who have a mitochondrial disorder? Absolutely. Does
it mean all kids with autism should have testing for mitochondrial diseases
as part of their evaluation? Maybe, but we need more research to see what
the link is before make it part of evaluating all possible cases of autism.

As for vaccines and mitochondrial diseases, Chuck Mohan, executive director
of the United Mitochondrial Disease Foundation,
said last week: "There
are no scientific studies documenting that childhood vaccinations cause or
worsen mitochondrial diseases, but there is very little scientific research
in this area." Again, until the court reveals the details of the
case, there's no way to know how the special masters deliberating this case
reached their decision.

So how do you know a child has autism?

Autism is what we call a clinical diagnosis, in which doctors make a diagnosis
based on a constellation of symptoms they observe. Unfortunately, there is
no specific lab test we have to objectively diagnose it. The importance of
this is that kids may have disorders that present with symptoms that are
similar to autism.

For example, kids with mental retardation or cerebral palsy can have autistic
features. In the case of kids who are developing normally and suddenly regress
into autismlike symptoms, there are other examples. Rett syndrome is one
such case. According to the National Institutes of Health, it is a "childhood
neurodevelopmental disorder characterized by normal early development followed
by loss of purposeful use of the hands, distinctive hand movements, slowed
brain and head growth, gait abnormalities, seizures, and mental retardation." It
goes on, and here is a key point: "Individuals with Rett syndrome often
exhibit autistic-like behaviors in the early stages."

Let's look at the simple example of fever. Fever is a symptom whose underlying
cause may be any number of things -- ear infections, pneumonia, certain cancers
or autoimmune disorders like lupus. In that sense, the language or behavioral
problems that we increasingly associate with autism could easily be manifestations
of other neurodevelopmental disorders. But unlike fever, there are very few
tests we have for language and behavioral problems to help us get to the
bottom of them, which makes the diagnosis much more subjective. In Hannah's
case, it appears that experts initially felt she was autistic, but once further
testing was done, they ably and accurately determined she has a mitochondrial
disorder.

So if it's not autism and nobody knows whether vaccines cause mitochondrial
disorders, why did the court come to this conclusion?

That's not clear, as the details of the case and its deliberation remain
sealed. But here are some issues to ponder. Experts tell us mitochondrial
disorders can be aggravated or unmasked by illness; an individual's mitochondria
will only go awry when there's stress placed on the body. The court document
mentions a series of illnesses Hannah developed between her diagnosis of
mitochondrial disease and after her vaccines. Two of these events occurred
within the expected timeline for a vaccine reaction. One—fever and irritability—seemed to be a reaction to the diphtheria, tetanus and pertussis vaccine.
This is a rare but well-known side effect of that vaccine. The second was
a fever and a rash that were diagnosed as a reaction to the chickenpox vaccine.

But Hannah had other many other infectious illnesses in that interval, which
were well beyond the timeline of vaccine side effects. Could these subsequent
illnesses have been the culprit, the aggravating factor, that tipped her
into her disorder, instead of vaccines? It wouldn't be unreasonable to conclude
this.

I also have some advice for government, whose efforts to reassure the public
about vaccine safety need vast improvement. Unseal the documents of the Poling
case so the public can hold officials accountable for the decision. Otherwise,
too many people will continue to believe that vaccines are autism's smoking
gun.